Device for cleaning filters



Jan. 13, 1948. MULLER 2,434,427

DEVICE FOR CLEANING FILTERS Filed April 21, 1958 4 Sheets-Sheet 1 {ffi ' NvENTo JACQUES MULLER Jah. 13, 1948. J. MULLER 2,434,427

DEVICE FOR CLEANING FILTERS Filed April 21, 1958 4 Sheets-Sheet 2 E '8 \NVENTOR LL JACQUES -M ULLER E a/7 #Waw' ATTYS.

Jan. 13, 1948. l MULLER 2,434,427

DEVICE FOR CLEANING FILTERS Filed April 21, 1958 4Sheehs-Sheet 3 INVENTOR JACQUES MULEER 5 L ATT'Ys.

Patented Jan. 13, 1948 UNlTED STATES PATENT OFFICE Application April21, 1938, 'Serial'No.-203,459 In France April 22, v1937 Section 3, Public'Law 690, August8, 1946 Patent expires April22, I957 8 Claims. (Cl.-210-167) This invention relates to industrial filters wherein a filtering material, through which the liquid to be purified passes, retains the impurities contained in the latter.

In filters of this type, the pores of the'filtering substance after beingin use fora predetermined period of time, are clogged by the retained impurities, which necessitates increasing thepressure for the purpose of ensuring the normal delivery of the filter, this clogging frequently rendering the filter inoperative.

It is therefore necessary to stop the filteror to disengage it from the circuit, for the purpose :of cleaning the filter, this stoppage or separating from the circuit being reduced to;a minimumso as not to interfere with the normal operation of a continuous installation.

The present invention relates moreparticularly to devices for cleaning industrial filters wherein the clogged filtering materials are freed from the impurities which they retain by causing the whole or a portion of the treated liquidto 'circulatein the opposite direction, either manually or automatically, whilst preferably using in the latter case the increase in pressure or the depression produced by the clogging for actuating a device for efiecting the reversing of the circulation of fluid.

In some cases it is possible to combine the cleaning on the counter current principle, which is operated independently, with the automatic operation by the addition of suitably locatedstop valves, 7

One of the preferred methods of cleaning filters by an independent member consists in'connecting the inlet for the liquid to be purified and the outlet for the purified liquid by a by-pass which shunts the filter, and producing in this by-pass, for example by a piston, the movement of the liquid.

In the case of cleaning by the automaticreversal of the direction of the liquid stream and for maintaining the continuous operation of an installation reference will be made to a system comprising two filters or two batteries of filters between which are located reversing members sensitive to the pressure or a pressure reduction in the fluid stream and which. when this exceeds a predetermined and adjustable limit,,places directly in circuit the cleaned filter and in .theshunt circuit the filter to be cleaned.

A preferred embodiment of this automatic ,reversing device may be provided with adouble-piston receiving alternately the pressure of the fluid ateach of its ends and. actuating the double shutter, the adjustment of the pressure of operation b'eing Obtained by causing a portion of the liquid to tbe .purifiedto pass into a venturi of which the neck .isconnectedby passages to the chambers of the filters.

Other features of the invention appear from the following description with reference to the accompanying drawings, which show by way of example, in

Fig. 1 a sectionalview of a filtering block of the known typewithxa by-pass and .manuallyactuatedpump, in

Fig. 2 a diagrammatic sectional view of two batteries of filters between which is located a reversing device sensitive to the pressure of the liquid stream, in

Fig. 3 a view partly in cross section and partly in elevation as on .the line 33 of Fig. 4 of-two filters between which is located a reversing device sensitivetto the. pressure of the liquid stream, in

Fig. 4 aplan view in cross section as :on the line 44 of Fig. 3, in

Fig. 5 a sectional view as on the line '55 of Fig. 4 and in Fig. 6 a sectional view as on the line6--fi of Fig.4.

Like numerals of reference indicate like parts in-the different views.

In Fig. '1 the liquid to be purified arrives through the passage I at the axis of a filtering block 2 and impinges upon a conical deflector 3 whichcauses the heavy impurities to be deposited under the action of gravity into a lower hopper 4 from which they are directed into a decantation chamber, not shown. The liquid, of which the major portion is purified, leaves at the periphery of the deflector 3, passes through the filtering block .2 provided with filtering rings 5 which retain the fine impurities and leaves purified by a central pipe 6 of the block leading to the outflow pipe 1.

Between the pipes 'l and 1 there is mounted in shunt a cylinder Bin which moves a double piston -9, l0 actuated from the outside by a handle II, operating a lever 'l 2 pivotally mounted at l2 and terminating in a roller I3 moving in a loop M of a rod 15 which connects together the two-pistons 9, l0.

When the filtering portions 5 of the block 2 are to be cleaned the filter is isolated from the circuit by closing the inlet and outlet valves, not shown, then the double piston 9, H) is actuated. The liquid which fills the filtering block then circulatesin both directions, that opposite the normal circulation entraining the materials which clog the pores from the filtering part of the filter, these materials being then conducted to the periphery of the filter and fall by gravity into the decantation chamber. The removal of the impurities is promoted by vibrations in the opposite direction produced by the alternating movement of the pistons, whilst their deposition under the action of gravity is efiectedin a relatively calm medium, due to the large cross-sectional area of the filter relatively to the outflow orifices of the cylinder 8. When there are used filtering elements which are arranged as shown in Fig. 1, that is to say in the form of truncated cones ar ranged vertically, the slope which results also promotes the removal by gravity of the impurities detached towards the periphery of the filter, but it will be understood that this arrangement is not given in a limiting sense, the systems shown being applied to any filter of the same type, It may be mentioned that with the conditions of operation of the device described the deposition of the impurities removed takes place very rapidly thus reducing the period of time during which the filter is out of circuit to a minimum.

In Figs. 2, 3, 4, 5 and 6 for the purpose of preventing stoppage, even temporarily, of the filtering system, there are provided two batteries of filters l4, l5 located on opposite sides of a central chamber l6, closed at the top at H.

The liquid to be purified arrives at l8 in the axis of the chamber I6 and escapes towards the batteries of filters l4, through the respective passages I9, forming an extension one with the other. 48 is the outflow passage for the purified liquid after leaving the filters.

The inner orifices of the passages I9, 23 may be closed alternately by a double sliding shutter 2|, 22, of which the rod 23 is connected at the middle 24 to a spring 25 which, when it has passed its central position slackens in one direction or the other so as to close one of the passages i9, 26.

In the path followed by the liquid to be purified between the passage l8 and the passages l9, 2i] is located a venturi 26 of which the neck 21 is connected by passage 28, 29 (provided with adjustable valves 33, 3! in Fig. 2), to the chambers 32, 33, respectively of the filters l4, IS.

The function of the Venturi tube is to produce low pressure in pipes 44 and 45 and in the lower ends of the chambers I6, 20. In the case of the chamber containing the active filter bed, the pressure reduction merely seeks oil back to the main inlet pipe, while in the case of the chamber containing the clogged filter bed the pressure reduction induces reverse flow of oil from the conduit connecting the outlets, through the-clogged filter bed. The valves 30, 3| in the passages 28, 29 are both always open and they permit regulation of the flow in these passages and of the degree of clogging at which reversal takes place.

Above the shutter 2|, 22 is located a cylinder 34 in which moves a double piston 35, 36, of which the rod 31 is connected by the link 38 pivotally mounted at 39, to the Pivot 24 of therod 23 of the double shutter 21, 22. One of the ends 43 of the cylinder 34 communicates by the passage 4| with the liquid inlet opening I9 and the other end 42 of the cylinder 34 communicates by the passage 43 with the liquid inlet opening 23 (Fig. 2).

In Figs. 3, 4, 5 and 6, the end 40 communicates by the passage 6| with the liquid inlet opening 20 and 42 by 62 with I9.

In the position shown in Figs. 2, 3, 4, 5 and 6 4 the block I5 is in operation, the liquid to be purified following the circuit indicated by the arrow 44.

A portion of the purified liquid passes on the counter-current principle into the filter l4 which it cleans and returns by passages 20, 40, M, 29 (Figs. 3, 4, 5 and 6), or the passage 29 (Fig. 2) into the neck 21 of the venturi in which the depression is adjustable by the valve 3| (Fig. 2). When the clogging of the filter l5 increases the pressure of circulation of the fluid, this pressure is transmitted by the passage 4| to the piston 36 in the case of Fig. 2, which is moved towards the right whilst entraining by its rod 3'! and the link 38, the double shutter 2|, 22 and the spring 24. When the latter has passed its vertical dead centre position it slackens suddenly, the shutter 2| closes the passage l9 and the circuit is reversed. In case of Figs. 3, 4, 5 and 6 the depression is transmitted by the passage l9 and 62 to the piston 35 which is moved towards the left whilst entraining by its rod 31 and the link 38 the double shutter 21, 22 and the spring 24 for closing the passage 40 and reversed the circuit.

In Fig. 2 the circuit follows the direction of the broken arrows 45 whilst cleaning the filter l5 and so on.

In Fig. 2 it will be seen that by reason of the venturi 21, the pressure and velocity of the fluid can be adjusted according to the degree of clogging of the latter by means of the valves 30, 3|.

Preferably and as shown in the drawing, the closure flaps 2|, 22 are located respectively in chambers 46, 41 in which they are not exposed to the direct action of the fluid stream thus preventing any defective operation or any premature operation.

The reversing system shown in Figs. 2, 3, 4, 5 and 6 may also be arranged for actuation by hand.

It will be understood that various modifications may be made without departing from the scope of the invention, thus for example when the mechanism for effecting the automatic reversal is mounted on the inlet orifices of the filters and operates by pressure on the charging circuit of the pump, it is possible, if desired, to mount it on the suction circuit. For this purpose it is sufficient to place the automatic reversing mechanism on the outlet orifices of the filter, the operation being then obtained by depression.

I claim:

1. A device of the character described, comprising two filter chambers, a filter bed in each chamber, each chamber having an inlet and an outlet, a conduit for supplying liquid to be filtered to the inlets of said chambers, valves for closing the inlets of said chambers, means connecting said valves to open the inlet to one chamber when the inlet of the other chamber is closed, means responsive to the pressure on the inlet side of the filter in one chamber urging the valves to a position to close the inlet to said chamber, means responsive to the pressure on the inlet side of the filter of the other chamber urging the valves to a position ot close the inlet of said other chamber, whereby when one filter becomes clogged its inlet valve will be closed and the inlet valve of the other filter opened, a conduit connecting the outlets of the two filter chambers, and means for forcing filtered liquid issuing from one filter chamber in reverse direction through the other filter chamber to remove impurities settled on the filter in the latter chamber.

2. A device of the character described, comprising two filter chambers, a filter bed in each chamber, each chamber having an inlet and an outlet, .a conduit for supplying liquid to be filtered to the inlets of said chambers, valves for closing the inlets of said chambers, means connecting said valves to open the inlet to one chamber when the inlet of the other chamber is closed, means responsive to the pressure on the inlet side of the filter in one chamber urging the valves to a position to close the inlet to said chamber, means responsive to the pressure on the inlet side of the filter of the other chamber urging the valves to a position to close the inlet of said other chamber, whereby when one filter becomes clogged its inlet valve will be closed and the inlet valve of the other filter opened, a pivoted lever interposed between said pressure responsive means and the valves for transmitting actuating movement to the valves, spring means connected to said lever in toggle fashion for urging the valves from an intermediate position to a position wherein one of the valves is closed, a conduit connecting the outlets of the two filter chambers, and means for forcin filtered liquid issuing from one filter chamber in reverse direction through the other filter chamber to remove impurities settled on the filter in the latter chamber.

3. A device of the character described, comprising two filter chambers, a filter bed in each chamber, each chamber having an inlet and an outlet, a conduit for supplying liquid to be filtered to the inlets of said chambers, valves for closing the inlets of said chambers, means connecting said valves to open the inlet to on chamber when the inlet of the other chamber is closed, means responsive to the pressure on the inlet side of the filter in one chamber urging the valves to a position to close the inlet to said chamber, means responsive to the pressure on the inlet side of the filter of the other chamber urging the valves to a position to close the inlet of said other chamber, whereby when one filter becomes clogged its inlet valve will be closed and the inlet valve of the other filter opened, a conduit connecting the outlets of said chambers, a discharge outlet in said conduit, and a Venturi tube in the supply conduit, said Venturi tube being connected to the inlet ends of said chambers and adapted to create there a pressure reduction suflicient to induce reverse flow through the filter bed in the chamber whereof the inlet is closed by one of said valves.

4. A device of the character described, comprising two filter chambers, a filter bed in each chamber, each chamber having an inlet and an outlet, a conduit for supplying liquid to be filtered to the inlets of said chambers, valves for closing the inlets of said chambers, means connecting said valves to open the inlet to one chamber when the inlet of the other chamber is closed, means responsive to the pressure on the inlet side of the filter in one chamber urging the valves to a position to close the inlet to said chamber, means responsive to the pressure on the inlet side of the filter of the other chamber urging the valves to a position to close the inlet of said other chamber, whereby when one filter becomes clogged its inlet valve will be closed and the inlet valve of the other filter opened, a conduit connecting the outlets of said chambers, a discharge outlet in said conduit, a Venturi tube in the supply conduit, and conduits connecting the neck of the Venturi tube with the inlet ends of both chambers, said Ven- 6 turi tube'being adapted to-create. at said ends 2, pressure reduction.

'5. A device of the character described, :comprising two filter chambers'a filter bed ineachnhamber, each chamber having an inlet and an outlet, a conduit for supplying liquidtobe'filtered to the inlets of said chambers, :valves for closing :the inlets of said chambers, means connecting said valves to open the inlet to one chamber when the inlet of the other chamberis closed, means responsive to the pressure on the inlet side of the filter in one chamber urging the valves to aposition to close the inlet to said chamber, means responsiveto thepressure ontheinlet side of'the filter of the other chamber-urging the 'valves to a position to close theinlet of said other chamber, whereby when one filter becomes clogged its inlet valve will be-closed and the inlet valve of the other filter opened, a conduit connecting theoutlets of said chamber, a discharge outlet in said conduit, a Venturi tube in the supply conduit, conduits connecting the neck of the Venturi tube with the inlet sides of both chambers, and means in said last-mentioned conduits for controlling the flow of fluid therethrough.

6. A device of the character described, comprising two filter chambers, a filter bed in each chamber, each chamber having an inlet and an outlet, a conduit for supplying liquid to be filtered to the inlets of said chambers, a conduit connecting the outlets of said chambers, a, discharge conduit branching from said connecting conduit, valves for closing the inlets of said chambers, means connecting said valves to open the inlet to one chamber when the inlet of the other chamber is closed, means responsive to the pressure on the inlet side of the filter in one chamber urging the valves to a position to close the inlet to said chamber, means responsive to the pressure on the inlet side of the filter of the other chamber urging the valves to a position to close the inlet of said other chamber, whereby when one filter becomes clogged its inlet valve will be closed and the inlet valve of the other filter opened, a Venturi tube in the supply conduit, and conduits connecting the neck of the Venturi tube with the inlet sides of both chambers to create a suction on the inlet side of the clogged filter chamber and cause a portion of the filtered fluid flowing in the conduit connecting the chamber outlets to be drawn from the outlet to the inlet side of the filter out of service.

7. A device of the character described, comprising two filter chambers, a filter bed in each chamber, each chamber having an inlet and an outlet, a conduit for supplying liquid to be filtered to the inlets of said chambers, a conduit connecting the outlets of said chambers, a discharge conduit branching from said connecting conduit valves for closing the inlets of said chambers, means connecting said valve to open the inlet to one chamber when the inlet of the other chamber is closed, means responsive to the pressure on the inlet side of the filter in one chamber urging the valves to a position to close the inlet to said chamber, means responsive to the pressure on the inlet side of the filter of the other chamber urging the valves to a position to close the inlet of said other chamber, whereby when one filter becomes clogged its inlet valve will be closed and the inlet valve of the other filter opened, a Venturi tube in the supply conduit, conduits connecting the neck of the Venturi tube with the inlet sides of both chambers to create a suction on the inlet side of the clogged filter chamber and, cause a portion of the filtered fluid flowing in the conduit connecting the chamber outlets to be drawn from the outlet to the inlet side of the filter out of service, a pivoted lever interposed between said pressure responsive means and the valves for transmitting actuating movement to the valves, and spring means connected to said lever in toggle fashion for urging thevalves from an intermediate position to a position wherein one of the valves is closed.

8. A device according to claim 6, in which the closure valves are located in chambers by which they are not exposed to the dynamic action of the liquid to be purified.

JACQUES MULLER.

REFERENCES CITED The following references are of record in the file of this patent:

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